Apparatus for extracting liquid from a fiber formation



April 30,- 1963 R. M.-'NEWMAN, JR 3,087,538

APPARATUS FOR Exmc'rmc LIQUID FROM A FIBER FORMATION Filed April 15. 1960 s Sheets-Sheet 1 BY M E96 ATTORNEY A ril 30, 1963 R. M. NEWMAN, JR

v APPARATUS FOR EXTRACTING LIQUID FROM A FIBER FORMATION 3 Sheets-Sheet 7B Filed April 15. 1960 ATTORNEY A ril 30, 1963 R. M. NEWMAN, JR 3,037,538

APPARATUS FOR sxmcmc rirqum FROM A FIBER FORMATION Filed April 15. 1960 s Sheets-Sheet s INVENTOR BY /4 fiz w ATTORNEY United States Patent M 3,087,538 APPARATUS FOR EXTRACTING LIQUID FROM A FIBER FORMATION Ralph M. Newman, In, 325 S. Charlevoix Place, Romney, W. Va. Filed Apr. 15, 1960, Ser. No. 22,454 Claims. (Cl. 162-297) This invention relates to an apparatus for extracting liquid from a newly formed fiber formation. More particularly, it concerns an apparatus for extracting liquid from a newly formed fiber formation on a travelling pervious wire of the type used in Fourdrinier type of paper machinery.

In the manufacture of paper, pressed boards and other products which are formed most expeditiously as a continuous web, Fourdrinier machines have been widely accepted and are commonly used. Ina Fourdrinier machine, a fiber slurry is deposited on a fine mesh screen or wire which is supported at a point adjacent a head box by a breast roll and then proceeding in a direction away from the head box, generally horizontally by a plurality of table rolls, over a plurality of suction boxes to a couch roll where the newly formed web is transferred to a press felt for further processing and subsequently to the finishing operation. The purpose of thus providing a generally horizontal flight in the wire is to allow sufficient time for the fibrous material to be properly accreted on the wire and the liquid to be removed therefrom so that the newly formed web may be transferred to the press felt without danger of rupturing.

In conventional Fourdrinier machines the drainage about the head box and the table rolls mostly by gravity accounts for approximately 75 to 80' percent of liquid extraction, the remainder being left to mechanical removal by the suction boxes. While suction boxes have been found generally effective to remove the necessary amount of liquid from the fiber formation, they impose severe stresses on the Fourdrinier wire due to friction developed by suction applied perpendicularly to the direction of wire movement which in turn causes wear, breakage and other deleterous effects resulting in high maintenance costs. Also, to achieve the necessary amount of liquid extraction, it is conventional to employ a plurality of suction boxes in tandem to reduce suction pressures. While this is effective for the purpose intended, it increases the length of the machine and creates not only increased length of wire but also presents a space problem.

Accordingly, a principal object of this invention is to provide an apparatus for extracting liquid from fiber formations on a Fourdrinier Wire by which the problems previously incurred are effectively and substantially overcome.

Another object of this invention is the provision of a liquid extraction apparatus of the type referred to which greatly reduces the length of wire run necessary to effect the required amount of liquid extraction from a fiber formation.

A further object of this invention is that of providing an apparatus for extracting liquid from fiber formations on Fourdrinier wires which greatly reduces the frictional drag of the wire and thereby increases the useable life of the wire as well as decreasing the power costs in driving the wire.

Still another object of this invention is the provision of an apparatus of the type referred to which facilitates the combined effects of compaction and differential pressure type liquid extraction from a fiber formation on a Fourdrinier wire without imposing undesirable loading stresses on the wire and thereby reducing the power costs 3,687,538 Patented Apr. 30, 1963 required by apparatus heretofore available wherein liquid extraction was carried out solely by pressure differential.

Other objects and further scope of applicability of the present invention will be apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description, while indicating preferred embodiments of the invention, is given by way of illustration only since it will be made apparent to those skilled in the art that various changes and modifications can be made without departing in any way from the true spirit and scope of this invention.

In general, the aforementioned objects are accomplished by supporting at least a portion of a tensioned travelling pervious wire such as a Fourdrinier wire on a pair of spaced rolls and providing a pervious pressure roll between the spaced rolls in compacting engagement with the fiber formation on the side of the wire opposite from the spaced rolls to constrain the formation and wire in a generally arcuate path so that the tension in the wire operates to compress the formation against the pressure roll. Means are provided for developing a pressure differential across the formation while it is in contact with the pressure roll which means may be either a positive pressure source within the pressure roll, a negative or suction pressure developed in a catch pan or receptacle positioned beneath the pressure roll and in sealing engagement with the under side of the wire, or by both a positive pressure on the formation side of the wire and a suction pressure on the backside thereof.

A more complete understanding of the new and improved liquid extraction apparatus of this invention and its operation may be had by reference to the accompanying drawings, in which:

FIG. 1 is a fragmentary side elevational view illustrating the liquid extraction apparatus of this invention on one end of a conventional Fourdrinier machine;

FIG. 2 is an enlarged fragmentary cross-sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is an enlarged fragmentary cross-sectional view taken along line 3-3 of FIG. 2;

FIG. 4 is a fragmentary perspective view of the catch pan of this invention equipped with a modified seal structure;

FIG. 5 is a cross-sectional view of the seal taken along line 5-5 of FIG. 4;

FIG. 6 is a fragmentary elevational view illustrating still another form of seal construction adaptable for use with the liquid extraction apparatus of this invention;

FIG. 7 is a fragmentary elevation illustrating a modified form of the liquid extraction apparatus of this invention;

FIG. 8 is a fragmentary plan view of the wire supporting belt incorporated in the embodiment of FIG. 7;

FIG. 9 is a fragmentary cross-sectional view taken along line 9-9 of FIGURE 8;

FIG. 10 is a fragmentary cross-sectional view taken along line 10-10 of FIGURE 8;

FIG. 11 is a schematic showing of a preferred vacuum system adapted for use with the liquid extraction apparatus of this invention; and

FIG. 12 is a schematic view of still another modification of this invention.

Referring now to FIGURE 1 of the drawings, the liquid extraction apparatus of this invention is shown at the delivery end of a Fourdrinier machine which conventionally includes an endless travelling screen or wire 10 on which the fiber formation 12 is accreted and which is supported on a plurality of table rolls 14. As will be understood by those familiar in this art, while only three table rolls 14 are shown it is common practice to employ as many as 20 or more of these rolls to properly support the wire 10 as it passes from the breast roll, the head box,

and the making board, none of which are shown on the drawing since these items are commonly known and as such, in and of themselves, do not form part of this invention. As shown, after leaving the table rolls 14 the wire is supported on its back side by a receiving couch roll 16, a delivery couch roll 18 and then begins its lower or return run back to the breast roll (not shown) by passage about guide and tension rolls 20 and 22 respectively. It will be understood further that while only one guide roll 20 and one tension roll 22 is illustrated in the drawings as many of these rolls may be used as necessary to properly support and tension the wire 10.

In a conventional manner, the roll 22 is supported in end bearing blocks 24 which in turn are received between vertical ways 26 supporting at their upper ends a cap member 28. A threaded shaft 30 is afl'ixed to the bearing block 24 and associated with a nut 32 positioned above the cap 28 to regulate the vertical positioning of the roll 22 and thus the amount of tension in the wire 10.

Also, the receiving couch roll 16 and the delivery couch roll 18 per se are conventional and include suction boxes 34 and 36 respectively. Each of the couch rolls is supported on each end by a tubular shaft 38 suitably journaled in housings 40 which in turn are supported on standards 42. The standards 42, housings 40, are hollow and in fluid communication with the suction boxes 34 and 36 by the provision of ports 44 through the tubular shafts 38. In this manner, the housings and standards 40 and 42 respectively function not only to support properly the couch rolls 16 and 18 but also facilitate the evacuation of the suction boxes 34 and 36 respectively therein by use of a suitable vacuum system which will be described more fully hereinafter.

Having thus allocated the Fourdrinier wire 10 with which the liquid extraction apparatus of this invention may be used, it will be noted that the portion of the wire 10 between the couch rolls 16 and 18 is constrained to take a generally arcuate path by a pressure roll 46 and that a substantial portion of the wire in contact with the roll 46 is covered on its back side by an open top receptacle or catch pan 48. As will be seen from the description which follows below, the cylindrical or formation engaging surface of the roll 46 is pervious to gas; that the receptacle or catch pan 48 is provided with suitable seal means on its upper edge to make possible a substantial and effective pressure differential across the web or fiber formation 12; and that this pressure differential, along with the compressive action of the wire 10 on the formation 12 against the pressure roll 46 functions to extract liquid from the formation in a manner much more efiiciently than apparatus heretofore available.

In the embodiment illustrated in FIGURES l, 2, and 3, of the drawings, the pressure roll 46 includes on each end a bearing ring 50 of generally L shaped cross-section which is suitably aflixed such as by welding or the like to a cylindrical supporting grill indicated generally by the numeral 51 and formed of a plurality of circumferential members 52 spaced axially from one another by transverse of members 54. Spirally wrapped about the grill 51 is a supporting wire 56. As shown, the convolutions of the supporting wire 56 are evenly spaced and support a facing screen 58 having characteristics similar to the screen making up the Fourdrinier wire 10. To support the pressure roll in position properly between the couch rolls 16 and 18, a plurality of rolls 60 are received by the bearing rings 50 which bearing rolls are in turn rotatably supported on a trunnion plate 62. The plate 62 is in turn welded, riveted, or otherwise affixed to a block 64 having an upper under-cut groove to permit its being slidably received on the lower flange of a support beam 66. In that the organization illustrated in FIGURE 2 will be duplicated on the opposite end of the roll 46, two supporting beams 66 are provided and each is pivotally supported on one end by a standard 68 and on the other end by a pneumatic, hydraulic or mechanical jack 70 for regulating its pivotal position and thus the vertical position of the pressure roll 46. To accurately control the horizontal position of the roll 46 on the beam 66, an internally threaded boss 72 is provided and receives a threaded shaft 74 by which the block 64 may be accurately moved and positioned along the beam 66 and thereby accurately position the roll 46 properly between the couch rolls 16 and 18.

Extending centrally through the pressure roll 46 is a tubular conduit 76 having a plurality of perforations 78 therein so that a suitable fluid pressure medium such as steam, compressed air or the like may be fed to the interior of the pressure roll 46. A chamber 80 is provided in the lower interior of the roll '46 for the purpose of rendering more effective the fluid pressure medium supplied thereto, which chamber is established by a pair of generally radially extending plates 82 suitably affixed to the tubular conduit 76 such as by U-bolts 84. End walls 86 of the chamber terminate at their lower ends in chime seals 88 which frictionally engage the outermost ring 52 of the roll 46. To seal the ends of the plates 82 against the interior of the pressure roll grill 51, seal members 90 are provided, and further, the plates 82 are formed having a plurality of venting apertures or slots 92 which may be adjusted between opened and closed positions as desired by plates 94.

The receptacle or catch pan 48 is supported upwardly against that position of the wire 10 backed up by the roll 46 by suitable means not shown and may be removed by lowering on to rollers 96 and movement axially of the couch rolls 16 and 18. To effectively seal the upper portion of the receptacle against the wire, in one form of this invention the axially extending or side walls thereof terminate at their upper ends in wire contacting members 98 mounted on pivotal arms 100 and connected to a toggle linkage mechanism 102 so that the pressure exerted by the seal members 98 against the wire may be properly regulated. To seal the ends of the receptacle effectively against the wire '10, a pair of belts 104 are trained about pulley grooves 106 on each end of the couch rolls 16 and 18 and maintained under proper tension by a sheave 108 pivotally aflixed to the receiving couch roll standard 42 and biased to tension the belt by a headed rod 110 and spring 112. In this manner, the belts 104 are urged upwardly against the wire 10 and the pressure roll 46 to establish a travelling frictionless seal therewith. As shown in FIGURE 2, the belt makes frictional contact with a rub plate 114 on the end of the receptacle or catch pan 48.

Alternative forms of seal arrangements for the upper portion of the receptacle 48, are illustrated in FIGURES 4, 5, and 6, of the drawings. In the embodiment illustrated in FIGURES 4 and 5, the upper portion of the catch pan 48 supports a plurality of tubular resilient seal strips 116 which may be inflated through nipples 118. With this arrangement, the belts 104 need not be used.

Another embodiment of the seal structure satisfactory to effectively seal the upper portion of the receptacle 48 against the wire 10 is illustrated in FIGURE 6. In this instance, it is contemplated that the belts 104 will be used to seal the ends of the receptacle in a manner similar to the embodiment illustrated in FIGURES l to 3. To seal the sides of the receptacle, however, a roller 120 is provided suitably journaled in a trough 122 which in turn is flexibly mounted to the upper edge of the receptacle. The trough is adapted to contain a suitable liquid so that no gas may pass between it and the roller and further, the roller and trough is supported on a lever arm 124 by which the sealing pressure of the roll against the wire 10 may be regulated.

A pumping system for developing necessary suctions or negative pressures in each of the suction boxes 34 and 36 in the couch rolls 16 and 18 respectively as well as in the catch pan or receptacle 48, is shown schematically in FIGURE 11. As shown, the intake 126 of a motor driven pump 128 is connected to a header 130 fed by branch lines 132, 134, and 136. The branch lines 132 and 134 go directly to the couch roll suction boxes 34 and 36 respectively while the branch line 136 is connected to a chamber 138 which in turn is connected to the receptacle 48 through line 140. As will be understood by those familiar in the art, liquid removed by the suction boxes 34 and 36 or collected in the catch pan 48 may be fed from the chamber 138 or pump 128 to drain or to recovery apparatus.

In operation, the apparatus above described is particularly suitable to the Fourdrinier technique of accreting fiber formations wherein a fiber slurry is deposited on the travelling wire as it passes beneath the head box (not shown). Almost immediately, a substantial percentage of the liquid from the slurry passes through the wire leaving the fiber formation accreted thereon by gravity for the most part and by the time the formation reaches the last table roll 14, approximately 75 to 80 percent of the liquid has been extracted in most operations. Thus before the formation or web may be transferred to the press felt for subsequent processing and finishing, a substantial portion of the remaining 20 to 25 percent of the liquid in the formation must be removed. In the apparatus of this invention this liquid extraction is greatly expedited by the compressive action exerted on the formation by the tensioned wire 10 against the pressure roll 46. The facing screen 58 on the roll 46 moves at the same speed as the wire 10 in most operations so that the formation is not in any way upset or harmed, though it may be desirable to deliberately bulk or stretch the formation to achieve various surface eifects by adjusting the speed of the roll to a value different from that of the wire 10. Further, since the compressive force exerted on the formation is the result of tension in the wire 10, it is evenly compacted over the area thereof in contact with the roll 46.

While the compressive forces developed by the roll 46 and the wire 10 on the fiber formation 12 greatly assists in removal of liquid, the amount of extraction is considerably increased by a pressure differential which may be created across the formation by either the introduction of steam or other compressed fluid into the chamber 80*, by creating suction pressures in the catch pan or receptacle 48, or by combining the effects of pressure in the chamber 80 and vacuum or suction in the receptacle 48. If the steam chamber 80 is used alone or in combination with suction pressures in the receptacle 48, the vents 92 are covered by the plates 94 to permit the development of sufficient pressures in the chamber. If on the other hand, it is desired to use only the suction pressures developed by the receptacle or catch pan 48, without complementing the suction pressures with positive pressures in the chamber 80 then the vents 92 are opened to prevent negative pressures from developing in the chamber 80. Also, the vents 92 may be opened if it is desirable to provide a steam shower over the formation without subjecting it to positive pressures, again relying only on suction pressures in the catch pan 48.

To illustrate further modifications of apparatus by which the desirable results of this invention may be realized, reference may be had to FIGURES 7 to 10 and 12 of the drawings. In the embodiment shown in FIG- URE 7, the arrangement of the principal components, i.e., the wire 10, couch rolls 1 6 and '18, the pressure roll 46 and the catch pan 48 is the same as the apparatus shown in FIGURE 1 except that in this instance the wire is backed up with a perforate endless belt 142 underlying the wire 10 as it passes over the couch roll 16, under the pressure roll 46, over the couch roll 18 and under the guide roll 20. The belt 142 extends across the width of the wire 10 and is adjustably tensioned by a tension roll 144 of conventional construction. In this manner, the compressive stresses necessary to compact the formation 12 against the roll 46 may be developed largely by the belt thereby alleviating to some extent the tensile forces necessary in the wire 10.

The structural configuration of the belt 142 is shown in FIGURES 8, 9 and 10 and is such that free passage of fluids through the wire 10 and the fiber formation 12 is permitted. To effect this characteristic, the upper portion of the belt is formed having a plurality of channels 146 situated angularly with respect to the direction of belt travel and inter-connected by a plurality of grooves 148 leaving parallelogram-shaped raised portions 150 for supporting the back of the wire 10. The lower portion of the belt is formed having a plurality of slots 152 opening at the bottom of the channels 146. Further, the lower edge of the belt is equipped with a depending projection 154 which complements the shape of the pulley grooves 106 in the couch rolls 16 and 18 thereby to guide the belt as it passes over the rolls. Also, it will be noted that the belt terminates at its edges in a continuous portion 156 so that the perforated portion thereof is isolated to enhance the seal between the receptable 48 and the pressure chamber 80 across the wire 10 and formation 12.

As will be understood by those familiar in the art, belt 142 may be formed of any of several suitable materials such as textile reinforced rubber, various plastic materials or other materials which are sufficiently flexible to enable the belt to be trained about the rolls 16, 46, 18, 20, and 144.

As indicated, the operation of the embodiment illustrated in FIGURE 7 is identical to that of the arrangement illustrated in FIGURE 1 except that the compressive forces against the fiber formation 12 are augmented by the belt 142. This feature is desirable in that it relieves the wire 10 of much of the tensile stresses necessary therein to produce the desired compressive effect on the formation 12 and against the pressure roll '46.

'A still further modification of this invention is illustrated schematically in FIGURE 12. In this embodiment, the facing screen 58 on the pressure roll 46 is replaced by a travelling wire cloth 158. The wire cloth 158 is similar to the Fourdrinier wire 10 and is trained about guiding and take up rolls 160 and 162 to maintain the desired tension and alignment thereof. An advantage of this arrangement is that additional working area insofar as liquid extraction is concerned may be developed by the co-action of the wire mesh 158 against the formation as backed up by the receiving couch roll 16 thereby resisting centrifugal throw-off of the formation as it passes over this couch roll and further, the departure of the mesh 158 from the roll 46 may be advantageously used to direct the cloth screen 158 past appropriate cleaning and reconditioning devices.

In addition, the embodiment illustrated in FIGURE 12 contemplates at least two pressure rolls 164 positioned in the receptacle 48 under the pressure roll 46 to augment the liquid extraction. This is brought about by the pumping effect of the rolls in contact with the wet wire 10- in a manner similar to the pumping elfect of table rolls as will be understood by those familiar with this art. Further a suitable drive mechanism is illustrated in FIGURE 12 for rotating the couch rolls 16 and 18 synchronously with the pressure roll 46 by power developed in a motor 166. The drive system may be adapted to the other embodiments of the invention mentioned above and contemplates a drive belt 168 trained about a pulley 170 on the pressure roll 46. Pulleys 172 and 174 positioned concentrically with the pulley 170 are arranged to drive the couch rolls 16 and 18 through crossed belts 176 and 178 respectively. Other drive arrangements could be used, however, and may be more desirable, particularly where it may be desirable to drive the rolls at different speeds.

Thus, it will be seen by those familiar with this art that the above mentioned objectives may be fully realized by this invention. The arrangement of the tensioned wire 10, couch rolls 16 and 18, pressure roll 46 and receptacle 48 is such that a substantial and yet exceptionally uniform pressure may be exerted on the formation 12 to effectively express residual liquid therefrom without danger of upsetting the formation. While this compaction, by itself, is highly desirable, considerably more liquid extracting capacity is provided by the foraminous or pervious facing on the pressure roll 46 and the differential pressure g erated across this facing and the formation by pressure chamber 8%), suction by the receptacle 48, or both, thereby requiring much less wire run alloted to liquid extraction than an apparatus heretofore available. Yet, very little frictional drag and the deleterious effects thereof are imposed on the Wire 10 since surfaces which exert the most pressure thereon rotate and accordingly, move with the wire.

Moreover, as demonstrated by the foregoing description, the new and unique results of this invention can be achieved by several different structural embodiments, the basic apparatus being represented by the embodiments of FIGS. 1, 7 and 12 While variations in effective catch pan seal arrangements are shown in FIGS. 4, 5, and 6. Although these embodiments represent preferred forms, it

iscontemplated that still other forms might be used without departing from the true spirit and scope of this invention. For example, the wire could be fed about the pair of spaced couch rolls and the pressure roll in such a manner that it engages substantially the entire periphery of the pressure roll, thereby increasing the area of pressure extraction. Also it will be appreciated that by using various sizes of rolls as well as various combinations of wire tension, and pressure differentials, a host of difierent liquid extraction characteristics can be effected.

In view of the many possible variations which can be made in the apparatus of this invention, it is to be distinctly understood that the foregoing description is illustrative only and not limiting. Correspondingly, the true scope and spirit of this invention is to be determined by the appended claims.

I claim:

1. Apparatus for extracting liquid from a fiber formation on a Fourdrinier wire comprising a pair of spaced rolls; an endless, porous, flexible belt extending across the width of the wire and supporting the wire from one side thereof, said belt being trained about said rolls; means for tensioning said belt; a pervious pressure roll intermediate said spaced rolls engaging the formation on the other-side of the wire; and means for developing a pressure differential across the formation.

2. The-apparatus recited in claim #1 in which said pressure differential developing means comprises: means defining a pressure chamber in said pressure roll for developing a positive pressure against the formation; and a receptacle positioned between said spaced rolls and opening to said belt and the wire from said one side thereof opposite said pressure roll, and means cooperating with said belt to form seal means between the wire and said receptacle.

'3. The apparatus recited in claim 2 in which said seal means includes: an inflatable member mounted on the opened edges of said receptacle, said member being in continuous contact with said belt.

4. The apparatus recited in claim 2 in which said seal means includes a pair of wire contacting members flexibly connected to upper wall portions of said receptacle, and means for moving said members into transverse engagement with the belt and said pressure roll said lastmentioned means including lever arms supporting each end of said members.

5. The apparatus recited in claim 4 in which said contacting members include rollers in combination with a liquid trough for eflecting a seal between said rollers and said receptacle.

References Cited in the file of this patent UNITED STATES PATENTS 

1. APPARATUS FOR EXTRACTING LIQUID FROM A FIBER FORMATION ON A FOURDRINIER WIRE COMPRISING A PAIR OF SPACED ROLLS; AN ENDLESS, POROUS, FLEXIBLE BELT EXTENDING ACROSS THE WIDTH OF THE WIRE AND SUPPORTING THE WIRE FROM ONE SIDE THEREOF, SAID BELT BEING TRAINED ABOUT SAID ROLLS; MEANS FOR TENSIONING SAID BELT; A PERVIOUS PRESSURE ROLL INTERMEDIATE SAID SPACED ROLLS ENGAGING THE FORMATION ON THE OTHER SIDE OF THE WIRE; AND MEANS FOR DEVELOPING A PRESSURE DIFFERENTIAL ACROSS THE FORMATION. 